uid yet unobserved, given out from this
explosion, which rends oak trees, bursts stone-walls, lights
inflammable substances, and fuses metals, or dissipates them in a
calciform smoak, along with which great light and much heat are
emitted, or these effects are produced by the heat and light only thus
set at liberty by their synchronous and sudden evolution.

2. The curious circumstance of electric condensation appears from the
violence of the shock of the coated jar compared with the strongest
spark from an insulated conductor, though the latter possesses a much
greater surface; when vitreous electric ether is thrown on one side of
a coated jar, it attracts the resinous electric ether of the other
side of the coated jar; and the same occurs, when resinous ether is
thrown on one side of it, it attracts the vitreous ether of the other
side of it, and thus the vitreous electric ether on one side of the
jar, and the resinous ether on the other side of it become condensed,
that is accumulated in less space, by their reciprocal attraction of
each other.

This condensation of the two electric ethers owing to their reciprocal
attraction appears from another curious event, that the thinner the
glass jar is, the stronger will the charge be on the same quantity of
surface, as then the two ethers approaching nearer without their
intermixing attract each other stronger, and consequently condense
each other more. And when the glass jar is very thin the reciprocal
attractive powers of the vitreous and resinous ether attract each
other so violently as at length to pass through the glass by rupturing
it, in the same manner as a less forcible attraction of them ruptures
and passes through the plate of air in the production of sparks from
the prime conductor.

As these two ethers on each side of a charged coated jar so powerfully
attract each other, when a communication is made between them by some
conducting substance as in the common mode of discharging an
electrised coated jar, they reciprocally pass to each other for the
purpose of combining, as some chemical fluids are known to do; as when
nitrous gas and oxygen gas are mixed together; whence as these fluids
pass both ways to intermix with each other, and then explode; a bur
appears on each side of a quire of paper well pressed together, when a
strong electric shock is passed through it; which is occasioned by
their explosion, like a train of gunpowder, and consequent emission of